Courtship is initiated by the male making a loud, deep roar, called bellowing. With this bellowing, he not only makes female alligators aware of his availability, but declares territorial boundaries to other males nearby. Receptive females bellow in response.

Following courtship and mating, the female begins construction of a nest by piling up vegetation into a mound. An individual nest may be up to seven feet wide and three feet high. An average of 35 - 40 eggs are buried within the mound, incubated by the warmth that the vegetation provides as it decays. The female remains near the nest for the duration of the nine week incubation period, often fending off the predators of the eggs, like raccoons. As hatching time approaches, the babies emit a high-pitched grunting noise which signals to the female to remove the incubating layers of vegetation covering them.